Simplified models to simulate part load perfomances of air conditioning equipments

The    performances  of  air  conditioning  equipments, like heat pumps, chillers or air conditioners, derive not only from the operative thermal levels, but also from the building requirement trend which normally involves frequent reductions of the full capacity. Nowadays an increasing consciousness of the importance of part load working influence on the equipment long  term efficiency has stimulated the investigation about part load  working  behaviour  of the machine. Owing to the incredible lack of experimental data about this topic, suitable new tests in laboratory and field monitoring, expressly carried on, have shown the necessity of new algorithms. In this paper these new mathematical models and their implementation in building-plant  simulation  codes are presented. The results obtained by their use for the calculation of the seasonal  performances  of HVAC systems in  some typical  applications are also discussed.